## GFileInputStream

GFileInputStream — File input streaming operations

## Synopsis

    #include <gio/gio.h>

                        GFileInputStream;
    GFileInfo *         g_file_input_stream_query_info      (GFileInputStream *stream,
                                                             const char *attributes,
                                                             GCancellable *cancellable,
                                                             GError **error);
    void                g_file_input_stream_query_info_async
                                                            (GFileInputStream *stream,
                                                             const char *attributes,
                                                             int io_priority,
                                                             GCancellable *cancellable,
                                                             GAsyncReadyCallback callback,
                                                             gpointer user_data);
    GFileInfo *         g_file_input_stream_query_info_finish
                                                            (GFileInputStream *stream,
                                                             GAsyncResult *result,
                                                             GError **error);

## Object Hierarchy

      GObject
       +----GInputStream
             +----GFileInputStream

## Implemented Interfaces

GFileInputStream implements GSeekable.

## Description

GFileInputStream provides input streams that take their content from a file.

GFileInputStream implements GSeekable, which allows the input stream to jump to arbitrary positions in the file, provided the filesystem of the file allows it. To find the position of a file input stream, use `g_seekable_tell()`. To find out if a file input stream supports seeking, use `g_seekable_stream_can_seek()`. To position a file input stream, use `g_seekable_seek()`.

## Details

### GFileInputStream

    typedef struct _GFileInputStream GFileInputStream;

A subclass of GInputStream for opened files. This adds a few file-specific operations and seeking.

GFileInputStream implements GSeekable.

### g_file_input_stream_query_info ()

    GFileInfo *         g_file_input_stream_query_info      (GFileInputStream *stream,
                                                             const char *attributes,
                                                             GCancellable *cancellable,
                                                             GError **error);

Queries a file input stream the given `attributes`. This function blocks while querying the stream. For the asynchronous (non-blocking) version of this function, see `g_file_input_stream_query_info_async()`. While the stream is blocked, the stream will set the pending flag internally, and any other operations on the stream will fail with `G_IO_ERROR_PENDING`.

`stream` : | a GFileInputStream.
`attributes` : | a file attribute query string.
`cancellable` : | optional GCancellable object, `NULL` to ignore. [allow-none]
`error` : | a GError location to store the error occuring, or `NULL` to ignore.
Returns : | a GFileInfo, or `NULL` on error. [transfer full]

### g_file_input_stream_query_info_async ()

    void                g_file_input_stream_query_info_async
                                                            (GFileInputStream *stream,
                                                             const char *attributes,
                                                             int io_priority,
                                                             GCancellable *cancellable,
                                                             GAsyncReadyCallback callback,
                                                             gpointer user_data);

Queries the stream information asynchronously. When the operation is finished `callback` will be called. You can then call `g_file_input_stream_query_info_finish()` to get the result of the operation.

For the synchronous version of this function, see `g_file_input_stream_query_info()`.

If `cancellable` is not `NULL`, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error `G_IO_ERROR_CANCELLED` will be set

`stream` : | a GFileInputStream.
`attributes` : | a file attribute query string.
`io_priority` : | the I/O priority of the request.
`cancellable` : | optional GCancellable object, `NULL` to ignore. [allow-none]
`callback` : | callback to call when the request is satisfied. [scope async]
`user_data` : | the data to pass to callback function. [closure]

### g_file_input_stream_query_info_finish ()

    GFileInfo *         g_file_input_stream_query_info_finish
                                                            (GFileInputStream *stream,
                                                             GAsyncResult *result,
                                                             GError **error);

Finishes an asynchronous info query operation.

`stream` : | a GFileInputStream.
`result` : | a GAsyncResult.
`error` : | a GError location to store the error occuring, or `NULL` to ignore.
Returns : | GFileInfo. [transfer full]

## See Also

GInputStream, GDataInputStream, GSeekable